11:15 AM (Tues) | *Wild weather in the Mid-Atl./NE US from later Christmas Eve into early Christmas Day…heavy rain, damaging winds, strong thunderstorms ahead of cold front…quick freeze-up post-front*
Paul Dorian
Overview
A powerful cold front will come barreling towards the eastern seaboard later this week and it’ll bring some wild weather with it to the Mid-Atlantic/Northeast US from later Christmas Eve (Thursday) into early Christmas Day (Friday). Ahead of the front, there will be heavy rain, possible strong thunderstorms, and potentially damaging winds which, unfortunately, raises the prospects of power outages. It’ll become much milder as well on Thursday with temperatures likely flirting with the 60 degree mark for late day highs in places like DC, Philly and NYC. The combination of heavy rainfall and mild conditions will cause a rapid melting of snow and this is likely to lead to localized flooding in areas of poor drainage.
On the back side of the front, temperatures will drop rapidly following the heavy rain event to below the freezing mark in many spots resulting in a quick freeze-up of standing water on untreated surfaces. Snow accumulations of several inches are likely in the colder air mass across portions of the Ohio Valley and interior Mid-Atlantic/Northeast US. There can even be a brief changeover to sleet and/or snow in the I-95 corridor early Friday morning as the colder air rushes into the region, but a “flash freeze” is the greater concern.
Low-level winds are forecasted to be very strong on Thursday evening and this raises a “red flag” for the potential of damaging wind gusts and power outages as the front comes barreling through the Mid-Atlantic/Northeast US. Map courtesy Accu Weather (twitter Bernie Rayno), NOAA
Details
Christmas Eve (Thursday) is likely to begin with decent snow cover in many areas of the Mid-Atlantic/NE US, but a lot of this will be washed away by the time Christmas morning rolls around; especially, on the east side of the Appalachian Mountains. Heavy rain is likely later Thursday and Thursday night - just ahead of a strong Arctic cold front - and it’ll turn much milder with temperatures soaring through the 50’s in the DC-to-Philly-to-NYC corridor. In addition to the heavy rain and milder conditions, winds will become an important factor later Thursday and Thursday night with possible gusts past 50 mph at inland locations and perhaps as high as 70 mph along coastal sections – unfortunately, this raises the chance for power outages. Strong thunderstorms are likely to form along the cold front as it crosses the eastern states in a west-to-east fashion on Thursday night/early Friday. In fact, severe weather is possible across the Carolinas as this cold front barrels towards the east coast and this includes the threat of tornadoes.
12Z GFS surface forecast map for 1AM, Friday, December 25 features snow on the back side of a powerful cold front and heavy rain, strong winds on the front side. Map courtesy NOAA, tropicaltidbits.com
Behind the strong cold front, temperatures are likely to crash to below the freezing mark in many areas and this could result in a quick ice-up of leftover standing water on untreated surfaces. The rain will change to accumulating snow in the Ohio Valley and interior sections of the Mid-Atlantic/NE US with 3-6 inches possible in the region from West Virginia to western Pennsylvania to western New York State. There is even a chance for a brief period of sleet and/or snow in the I-95 corridor post-frontal passage in the overnight hours on Friday morning as the cold air floods the area, but the potential “flash freeze” is likely a bigger concern. High pressure takes control at week’s end and it’ll stay very cold on Saturday with highs struggling to reach the freezing mark in the DC-to-Philly-to-NYC corridor.
Widespread rainfall amounts of 1.50 to 2.50 inches will take place with the passage of the late week strong Arctic cold front and isolated areas will receive 3 or 4 inches. The combination of the heavy rainfall and milder conditions ahead of the front will likely lead to localized flooding in poor drainage areas. Map courtesy NOAA
Looking ahead, an energetic pattern is in the offing for next week across the central and eastern US. In fact, there will likely be multiple systems to monitor and this active pattern is quite likely to continue into early January as well. An early week storm is likely to bring rain and snow to the Mid-Atlantic/NE US and potentially very strong winds on its heels. Another storm is likely to be a threat late next week possibly to coincide with New Year’s Day. Trends in teleconnection indices and the potential of a “stratospheric warming” event suggest cold air outbreaks will continue into early January across the central and eastern US (see video for more details).
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com